This paper was originally intended to be a review of three groups only, Cuna, Condylocardia and Cyamiomactra, but it has been extended to cover most of the minute bivalves living on the coast of New South Wales. In the course of the investigation so many minute forms came under observation, many of rather obscure classification, that the opportunity was taken to study and draw them, and thus the scope of the paper was gradually extended. The term minute is not an arbitrary one, but is here taken to refer to shells less than about 3 mm. in size. An exception is Cunanax pisum Hedley, which is 6 mm. in height, but the other members of this family are all minute, so this species could hardly be excluded. The only really small shells not dealt with are certain deep water forms such as Cyrilla, Bathyarca, Cratis, Notomytilus and Pronucula. These were omitted either because of insufficient material, or because there was nothing new to add to the excellent work done by the late Charles Hedley.
Practically all the material here dealt with has been collected by my son John and myself in the last twenty years, and to my collecting partner must go most of the credit for picking out the rarities and novelties from shell sand and dredgings. To Mr. Tom Iredale my thanks are also due, for throughout he has given me the benefit of his great experience and much advice concerning the classification.
All types and specimens illustrated have been presented to the Australian Museum.